I think the camp setup as-is, is a pretty aberrant thing in a D&D game. I have kind of a long list of complaints about "camp", but I won't bother going into them since I wouldn't object to selling stuff directly from the camp "wares" category or whatever as an expediency thing. This is a place where time and carrying capacity ACTUALLY mattering somehow would improve doing something like that. Can't start our long rest for another 10 hours? Well, might as well schlep our crap to the merchant who agreed to buy it all like we're a low-rent moving company in desperate need of coin.
The inventory thing feels like a holdover from DOS2, especially since quite obviously the Charisma score of the character is influencing the price - in an actual game either you'd haggle, and it'd be the best qualified haggling person doing it, or you'd say "F it." and take the bulk rate to get rid of stuff. Hopefully they change that and don't stick to how "so independent" everyone in the group is. I'm not wild about the framing concept in this instance - let's form an adventuring party of people who don't want to go on an adventure together. It'd make a better book than a game.
